Researchers have found an "anxiety gene" which when switched on not only causes stress but increases our craving for sweets and comfort food.
They believe that the gene could be the reason why we are becoming an increasingly obese and stressful society. It could be the reason for the phenomenon "comfort eating".
Dr Alon Chen, a neuroendocrinologist at the Weizmann Institute in Israel, said: "We showed that the actions of a single gene in just one part of the brain can have profound effects on the metabolism of the whole body.
"In essence, stress may be turning us fat."
Few people lead stress-free lives these days which may, say experts, account for the rise in obesity triggered by the stress gene.
"Stress is definitely influencing every system in the body," said Dr Chen "It's not just causing anxiety, depression and post-traumatic stress disorder but is influencing metabolic syndromes such as obesity."
In the study, published in the Proceedings of the National Academy of Sciences, the researchers have discovered that there's a "stress switch" that seems to lead to diabetes and obesity.
The Israeli researchers created their own method for changing the activity of the gene in the brain, causing it to release varied amounts of a protein called Ucn3.
They discovered that increased levels of Ucn3 caused anxiety and changes in metabolism.
With increased levels of Ucn3, the bodies of mice used more sugar and less fatty acids and metabolic rates increased, showing the first stages of type 2 diabetes...